The supermodel was celebrating the milestone age at China Tang at the Dorchester hotel but her bash - which was attended by 30 friends including Stella McCartney and Nick Grimshaw - caused complaints because of loud singing.

A fellow diner told the Daily Mirror newspaper: "We nearly went to a karaoke bar but decided to have a sophisticated meal here instead.

"But we might as well have gone to the bar as this place feels just like one.

"We're having to shout over the singing in order to hold a conversation. It's ridiculous."

It is said Kate - who turned 40 on Thursday 01.16.14) - and her guests started drinking cocktails and loudly singing songs by The Rolling Stones, INXS and Fleetwood Mac.

The occasion was marked by a heartfelt letter from fellow model Naomi Campbell, who described her as her "little sister."

She wrote: "She's like my little sister, and 40 or not she's still my little sister ... I'm proud of Kate, I'm very proud of her, I think what she's done and what she's still doing is phenomenal.

"There was never any jealousy between us. We were always supportive of each other and happy for one another. I respect her husband Jamie tremendously; I love him. Kate is also an amazing mother."